Phonograph-record arm mounting



Aug. 9, 1949.

R. M. CAIN PHONOGRAPH-RECORD ARM MOUNTING Filed June 14, 1946 INVENTOR.ROBERT M. CAIN mku lw A r TORNE Vs Patented Aug. 9, 1949PHONOGRAPH-RECORD ARM MOUNTING Robert M. Cain, Charlotte, Mich, assignorto Wilcox-Gay Corporation, Charlotte, Mich, a corporation of MichiganApplication June 14, 1946, Serial No. 676,777

6 Claims. Cl. 274--23) My present invention relates to phonographs andmore particularly to a novel mounting for a record cutting arm whichwill facilitate the raising of the cutting arm out of engagement with arecord blank on the turn table and which will facilitate lowering thecutting arm into engagement with the record blank, and also intoengagement with driving means for the cutting arm.

My present invention is an improvement on prior Patent No. 2,351,948assigned to the assignee of the present invention. My invention isdesigned to replace the specific mounting of the cutting arm shown inthe said patent while, nevertheless, retaining the same type of lateraldriving means for the cutting arm and the same type of mounting for thecartridge which carries the cutting stylus.

The cutting arm should be so arranged when disengaged from the recordblank or the turn table that it will remain in the disengaged positionwithout further attention, while it may readily, however, be returned tothe engaged position.

Previously, it has been deemed necessary to rotate the cutting armvertically through an arc of slightly more than 90 in order to ensurethat the cutting arm will remain in the raised position. Also, this fullrotation of the cutting arm to the vertical position has heretofore beenthought necessary in order efiectively to disengage the driven means forthe cutting arm from its driving means.

The principal object of my invention is the mounting of the cutting armor other tone arm of a phonograph in such a manner that it may be raisedand be maintained in the raised position on upward rotation thereofthrough a relatively small arc of the order of 45 and less.

Another object of my invention is the arrangement of a cutting arm orother tone arm for a phonograph in such a manner that the driving meanstherefor may be readily disengaged on rotating the cutting armvertically through a substantially smaller angle.

It will, of course, be obvious that my invention is equally applicableto the pick up arm of a phonograph in order to maintain the same inraised position when it is desired to disengage it from the turn table.

The foregoing and many other objects of my invention will becomeapparent in the following description and drawings in which:

Figure 1 is a side view partly in cross-section showing my novel cuttingarm mounting with the cutting arm lowered,

Figure 2 is a view corresponding to that of Figure 1 showing the cuttingarm raised.

Figure 3 is a cross-sectional view taken on line 3-3 looking in thedirection of the arrows.

Referring now to the figures, the turn table mounting plate ID of thephonograph is supported in any suitable manner in the top of thecabinet. Suitable drive mechanism, not shown, but having the formgenerally illustrated in prior Patent No. 2,351,948, drives the turntable II carrying the record blank l2. Rotation of the turn table I byits drive means causes the turn table H to rotate its spindle l3.Spindle I3 is connected to the gear box l4 beneath the mouting plate Inand through the worm gear speed reducing ele ment housed in the gear boxI 4 drives the elongated worm gear l5. The drive for the gear I5 is alsoas shown in the said prior Patent No. 2,351,948. Worm gear 15 is engagedby the knife edge pawl 16 on the end of the flexible member l! securedin any suitable manner as by the rivets I8 to the feed arm I9.

The flexible member I! has vertical compliance but is so attached to thefeed arm l'9 that it has no lateral compliance with respect thereto.Consequently, any movement imparted to the pawl It by rotation of thescrew l5 will result in exactly corresponding movement of the feed arm[9. An adjusting screw 20 is mounted at the outer end of the feed arm l9and held in adjusted position by the lock nut 2| in order to adjust theposition of pawl l6 so as to properly engage the screw 15.

The cutting arm 25 carries the cutting stylus 26 at one end and the saidstylus is held in place in the cartridge not shown by the set screw 21.

The mounting of the stylus in the cutting arm and the arrangement of thecartridge in the cutting arm 25 is exactly like that shown in the saidprior Patent No. 2,351,948; this arrangement is not specificallydescribed herein since it forms no part of the present invention.

The rear end of the cutting arm is pivotally mounted by means of thebearings 30 on the side flanges 3| of the rotatable platform 32.Bearings 30 as shown are preferably needle bearings of a well-known typecomprising an adjustable pointed screw 33, 33 threaded throughappropriately threaded openings in the side flanges 35, 35 of thecutting arm 25 and entering into conical sockets indicated at 3B, 36 ofthe side flanges 3| of the platform 32.

The cutting arm 25 is thus readily rotatable vertically with respect tothe platform 32 but has no lateral compliance or movement with respectto the platform 32.

When the cutting arm 25 is lowered, the position of the stylus 26 withrespect to the record blank E2 on the turn table may be roughly adjustedby adjusting the set screw 50 threaded into the forward end of the topof platform 32, the height of the set screw being maintained by the locknut The under-side of the cutting arm 25 rests on the "set'screw 5|]thereby determining the degree to which the cutting arm 25 may berotated downwardly about the bearings 35, thus providing a roughadjustment of the position and angle of the cutting stylus 26. Thisarrangement is also shown in the aforesaid prior Patent No. 2,351,948.Fine adjustment of the position and angle of the cutting stylus 26 maythen be obtained by adjustment of cartridge which carries stylus orneedle 26 also in accordance with the disclosure of the said priorPatent No. 2,351,948.

Platform 32 is secured in any suitable manner to the top of post 46 andis keyed thereto so that it is necessarily rotatable therewith. Post 26extends through opening 4| in the journal 42 and opening 43 in the'baseplate I0, so that the post 4|! extends beneath the base plate l6.

Feed arm I9 is rigidly secured to the post 56 so that the post 40 isnecessarily rotatable in accordance with lateral movement of the feedarm |9. A compression spring 45 surrounds the post 49 and is capturedbetween the under surface of the base plate H) and the upper surface ofthe feed arm l9. Accordingly, the post 40 and feed arm l9 together withthe platform 32 are biased downwardly to the position'shown in Figure 1.

Each of the flanges 3| of the platform 32 is provided with a downwardextension 55 having a substantially vertical surface 56 on either sideof a portion of the journal 42. Each of the vertical edges 56 is alsoprovided at its lower end with a recess 51 having the detent 5B. Therecess 5'! is, as shown, spaced substantially forward of the verticaledge 56.

A U-sha'ped wire 60 having horizontal portion 6| and the leg portions62, 62 is pivotally connected at its opposite ends at 63, 63 in oppositeappropriate openings in the opposite flanges 35, 35 of the cutting arm25. Each of the legs 62 of the U-shaped wire 6|] forms a link.

As will be obvious from the drawings, the pivotal connection 63 is onthe opposite side of the bearings 30 from the stylus 26. A toggle isthus formed having one imaginary link indicated by the dotted line 10between bearings 30 and pivot 63 and having as its other link the leg 62of the llglshaped wire 60. This toggle is formed on each s1 e.

Pivot 63 is the knee pin of the toggle |||-62. The end pivot 30 oflinkH! can move vertically with the post 40, but has no other movement. 7

When the cutting arm 25 is in the lowered position of Figure 1, thelower end pivot of link 62 is fixed by reason of the fact that thehorizontal arm 6| of the U-shaped wire bears against the verticalsurface 56. of the downwardly depending arm 55 of platform 32, and alsoby reason of the fact that the portion 6| of the wire rests on the uppersurface of journal 42.

The linkor leg 62 of the toggle I'll-62 may thus rotate about the pivotthereby formed, while the pivot remains fixed; this pivot remains fixedas 'long as any portion of the verticalsurface 56 is engaged by portion6| of the U-shaped wire.

When, now,'the forward end of the-cutting arm 25 in the region of thestylus 26-is manually 4 engaged and lifted, the cutting arm is rotatedupwardly about the pivot 3|! and the pivot 53 on the cutting arm isforced down. Pivot 63 must move in accordance with the rotationalmovement of the cutting arm 25.

The pivot formed by the meeting of horizontal legs 6| of the U-shapedwire, the upper surface of the journal 42 and theverticalsurface 56 is astationary pivot during the initial upward movement of the cutting arm25. Therefore, with the outer lower pivot of leg 62 thus fixed and withthe knee pin of the toggle 63 being forced down, the opposite outerpivot of the toggle 63' must move upwardly. But this other pivot 36 issecured to the platform 32, which in turn is secured to the post 40which is also secured to the feed arm l9. Consequently, the post 40,platform 32 and feed arm I9 must move up.

This upward movement disengages the pawl I6 from the Worm |5 so that thecutting arm 25 is disconnected'from its drive when it is raised.

As shown, it is necessary to raise the cutting arm 25 to an angle ofnot'more than of its original down position in order to disengage thecutting arm from its drive.

Previously, however,'.as shown in the aforesaid Patent No. 2,351,948, itwas thought necessary to raise the cutting arm through slightly morethan 90 in order to maintain the cutting arm in raised and disengagedposition. In fact, as shown in the aforesaid patent, the cutting arm 25was raised to a point where the units which corresponded to the toggle10-62 broke through center so that the compression spring could evenassist in maintaining the cutting arm raised.

My present invention is designed so that it will be necessary only toraise the cutting arm 25 sufiiciently to disengage the pawl l6 from thescrew l5 and so that when thus disengaged, the cutting arm 25 willremain in raised position as shown in Figure 2. This is accomplished bythe recessed surface 51 and the detent 58 in the vertical surface 56 ofthe dependent members 55 of the platform 32.

When, as shown in Figure 2, cutting arm 25 has been raised sufficientlyto disengage pawl l6 from screw |5, the member 55 has been raised to asufficient height so that the recess 51 moves opposite the horizontalleg 6| of the U-shaped wire. The outer pivot of the link 62 of thetoggle Hie-62 now shifts over to the left to the position defined by theintersection of surfaces 51 with the upper surface of journal 42. Whenthis outer pivot of link 62 of the toggle 15-62 thus shifts over to theleft, the cutting arm 25 now rises without further lifting the post 46,platform 32 or feed arm I9.

Further lifting of post 40 and feed arm I9 is no longer necessary sincethe disengagement of pawl Hi from screw 5 hasalready been obtained; sothat the displ'acementto the left (with respect to Figures 1 and 2) ofsurface 51 from surface 53 determines the extent to which the cuttingarm 25 will be further raised after the upward movement32 of post 40andfeed arm l9 has stopped. Thesurface 51 may be displaced sufficientlyfrom surface 56 to even permit movement of the cutting arm 25 to fullvertical position without any further upward movement of feed arm l9,post Ail. ofplatform 32'.

The detent surface 58', if surface 51 is displaced sufficiently fromsurface 56, may be horizontal and thereby-resist the compression spring45 in its effort to return theelements to position of Figure 1. In orderto avoid any undesired return of the elements from the position ofFigure 2 to the position of Figure 1, the surface 58 may be made as adetent surface, as shown, so that the horizontal portion 6| of theU-shaped wire 6!] snaps into the detent 58.

The compression spring 45 is so designed that by itself it cannot causethe horizontal portion 6| of the wire 60 to slide out of the detent andthe arm 25 remains in the position of Figure 2. The compression spring45 and the angle of the detent 58 is, however, so designed that downwardmanual pressure on the stylus end of the cutting arm 25 will cause thehorizontal portion 6| of the U- shaped wire 60 to ride out of thedetent, thus pulling the portion 6! of wire 6!] toward the right andpermitting the compression spring 45 to pull the post 40, platform 32and feed arm l9.

By means of the foregoing, it is thus possible to design and dimensionthe elements to allow for the limited travel necessary for post 40 inorder to effect complete disengagement. Previously, as in Patent No.2,351,948, the screw I 5 and feed arm I9 were placed sufiiciently belowthe base plate I so that the feed arm l9 has full clearance to risethrough the distance made necessary by the full 90 upward rotation ofthe cutting arm 25. Since the link 62 of the cutting arm 25 is now ineffect disconnected from its pivot after a relatively small upwardrotation of the cutting arm 25, the cutting arm 25 may be raised to anyheight and rotated through any are while only the first 30 or so ofupward rotation of the cutting arm actually results in raising the feedarm l9.

Accordingly, the post 40 may be made shorter and the screw l may bebrought up closer to the under-side of the base plate since the feed arml9 need not be raised to the same height. This provides for a morecompact, better operating and less expensive structure.

Also, by the provision of the detent surface 58, the necessity forraising the cutting arm 25 through a full 90 .arc in order to maintainit in the up position is obviated and the cutting arm need merely beraised through an arc of 30 to 45 to be maintained in the up position.This makes it possible to provide a shallower well in the top of thecabinet for the phonograph apparatus where it is desired that the coverbe closed with the cutting arm 25 in the up position.

In the foregoing, I have described my invention solely in connectionwith a specific preferred embodiment thereof. Since many variations andmodifications of my invention will now be obvious to those skilled inthe art, I prefer to be bound not by the specific disclosures hereincontained but only by the appended claims.

I claim:

1. In a phonograph, an arm; means at the front end of said arm forcarrying a needle in a position substantially normal to said arm; arotatable vertical post; a platform secured thereto; the rear end ofsaid arm being pivotally connected to said platform; said arm beingrotatable about said pivot from a substantially horizontal position to aposition wherein the front end thereof is raised through a substantialangle; a portion of said rear end of said arm projecting beyond saidpivot; a journal for said post; said post being rotatable angularly andslidable vertically in said journal; said journal having a horizontalsurface; a downwardly extending projection from said platform; an edgeof said projection intersecting the plane of the horizontal surface ofsaid journal; a link connected at one end to the rear portion of the armextending beyond the pivot thereof and, at the other end, bearingagainst the angle defined by said edge of said platform projection andthe horizontal surface of the journal; raising the front end of said armcausing said link to exert downward pressure on said journal surface toraise said post.

2. In a phonograph, an arm; means at the front end of said arm forcarrying a needle in a position substantially normal to said arm; arotatable vertical post; a platform secured thereto; the rear end ofsaid arm being pivotally connected to said platform; said arm beingrotatable about said pivot from a substantially horizontal position to aposition wherein the front end thereof is raised through a substantialangle; a portion of said rear end of said arm projecting beyond saidpivot; a journal for said post; said post being rotatable angularly andslidable vertically in said journal; said journal having a horizontalsurface; a downwardly extending projection from said platform; an edgeof said projection intersecting the plane of the horizontal surface ofsaid journal; a link connected at one end to the rear portion of the armextending beyond the pivot thereof; and, at the other end, bearingagainst the angle defined by said edge of said platform projection andthe horizontal surface of the journal; raising the front end of said armcausing said link to exert downward pressure on said journal surface toraise said post; said projection moving up as said post is raised; arecess in said edge of said projection; said link shifting its lowerpivot laterally as said recess moves opposite the lower end thereof topermit said arm to be raised further while said post remains at thelevel reached thereby just before said recess was reached.

3. In a. phonograph, an arm; means at the front end of said arm forcarrying a needle in a position substantially normal to said arm; arotatable vertical post; a platform secured there to; the rear end ofsaid arm being pivotally connected to said platform; said arm beingrotatable about said pivot from a substantially horizontal position to aposition wherein the front end thereof is raised through a substantialangle; a portion of said rear end of said arm projecting beyond saidpivot; a journal for said post; said post being rotatable angularly andslidable vertically in said journal; said journal having a horizontalsurface; a downwardly extending projection from said platform; an edgeof said projection intersecting the plane of the horizontal surface ofsaid journal; a link connected at one end to the rear portion of the armextending beyond the pivot thereof; and, at the other end, bearingagainst the angle defined by said edge of said platform projection andthe horizontal surface of the journal; raising the front end of said armcausing said link to exert downward pressure on said journal surface toraise said post; said projection moving up as said post is raised; arecess in said edge of said projection; said link shifting its lowerpivot laterally as said recess moves opposite the lower end thereof topermit said arm to be raised further while said post remains at thelevel reached thereby just before said recess was reached; means biasingsaid post downwardly; a detent in said recess engaging the end of saidlink and maintaining said arm in lifted position against the force ofsaid biasing means.

4. In a phonograph, an arm; means at the front end of said arm forcarrying a needle in a position substantially normal to said arm; arotatable vertical post; the rear end of said arm being pivotallyconnected to said post; said arm being rotatable about said pivot from asubstantially horizontal position to a position wherein the front endthereof is raised through a substantial angle; a portion of said rearend of said arm projecting beyond said pivot; a journal for said post;said post being rotatable angularly and slidable vertically in saidjournal; said journal having a horizontal surface; the upper end of saidpost having a member secured thereto extending therefrom toward thefront of the arm; said member having a downwardly extending projectionintersecting the plane of the horizontal surface of said journal; a linkconnected at one end to the rear portion of the arm extending beyond thepivot thereof, and, at the other end, bearing against the angle definedby the edge of said projection and the horizontal surface of saidjournal; raising the front end of said arm causing said link to exertdownward pressure on said journal surface to raise said post.

5. In a phonograph, an arm; means at the front end of said arm forcarrying a needle in a position substantially normal to said arm; arotatable vertical post; the rear end of said arm being pivotallyconnected to said post; said arm being rotatable about said pivot from asubstantially. horizontal position to a position wherein the front endthereof is raised through a substantial angle; a portion of said rearend of said arm projecting beyond said pivot; a journal for said post;said post being rotatable angularly and slidable vertically in saidjournal; said journal having a horizontal surface; the upper end of saidpost having a member secured thereto extending therefrom toward thefront of the arm; said member having a downwardly extending projectionintersectin the plane of the horizontal surface of saidjournal; 9, linkconnected at one end to the rear portion of the arm extending beyond thepivot thereof, and, at the other end, bearing against the angle definedby the edge of said projection and the horizontal surface of saidjournal; raising the front end of said arm causing said link to exertdownward pressure on said journal surface to raise said post; saidprojection moving up as said post is raised; a recess in said edge ofsaid projection;

said link shiftlngits f lower pivot laterally as said recess movesopposite the lower end thereof to permit said arm to be raised furtherwhile said post remainsat the level reached thereby just before saidrecess wasreached.

6. in a phonograph, an arm; means at the front end of said arm forcarrying a needle in a position substantially normal to said arm; arotatable vertical post; the rear end of said arm being pivotallyconnected to said post; said arm being rotatable about said pivot from asubstantially horizontal position to a position wherein the front endthereof is raised through a substantial angle a portion of said rear endof said arm projecting beyond said pivot; a journal for said post; saidpost being rotatable angularly and slidable vertically in said journal;said journal having a horizontal surface; the upper end of said posthaving a member secured thereto extending therefrom toward the front ofthe arm; said member having a downwardly extending projectionintersecting the plane of the horizontal surface of said journal; a linkconnected at one end to the rear portion of the arm extending beyond thepivot thereof, and, at the other end, bearing against the angle definedby the edge of said projection and the horizontal surface of saidjournal; raising the front end of said arm causing said link to exertdownward pressure on said journal surface to raise said post; saidprojection moving up as said post is raised; a recess in said edge ofsaid projection; said link shifting its lower pivot laterally as saidrecess moves opposite the lower end thereof to permit said arm to beraised further while said post remains at the level reached thereby justbefore said recess was reached; means biasing said post downwardly; adetent in said recess engaging the end of said link and maintaining saidarm in lifted position against the force of said biasin means.

ROBERT M. CAIN.

REFERENCES CITED UNITED STATES PATENTS Name Date Gay June 20, 1944Number

